The present invention relates to a vacuum deaeration device in which a transmission film for allowing only gas to pass therethrough and preventing liquid from being transmitted is mounted within a vacuum container, a pressure within the vacuum container is reduced by a vacuum pump or the like to deaerate resolved gas from liquid (deaerated liquid) contacted with the aforesaid transmission film. More particularly the invention is a vacuum deaeration device suitable for removing resolved gas from liquid (deaerated liquid) in various kinds of production process facilities, such as a liquid chromatograph as well as various kinds of physical and chemical and analytical devices, pharmaceutical engineering, semi-conductors and liquid crystals.
Analytical processing is performed using analytical equipment, such as a liquid chromatograph device. Resolved gas is removed (deaerated) from sample liquid or solvent, or liquid to improve reliability in measurement data. A fluorine transmission film for allowing only gas to pass therethrough and preventing liquid from being transmitted is used at a location of the deaeration device in contact with the foresaid sample liquid or solvent, or liquid.
The transmission film used in this type of deaeration device is usually manufactured by a method wherein residual gasoline substances (e.g., naphtha or white oil) are added to and mixed with a powder fluorine plastic substrate to form paste. The paste material is extruded and baked under a relatively high temperature (approximately 100xc2x0 C. to approximately 400xc2x0 C.).
At this time, liquid of a relatively low boiling point such as the aforesaid gasoline residuals is evaporated during the baking operation and removed. However, actually, liquid of relatively low boiling point, in particular, aromatic substances and olefin substances are not completely evaporated and a relatively small amount of the substances remain in the transmission film. These remaining substances in the transmission film are freely separated when liquid (deaerated liquid) is contacted with the transmission film, resolved into deaerated liquid, and bad influence (a measurement error) is applied to the measurement result performed by the liquid chromatograph device or quality keeping controls in various kinds of production processes.
The present invention overcomes the aforesaid disadvantages as above in the prior art. Specifically, the present invention is directed to a vacuum deaeration device having no possibility that aromatic substances or olefin substances applying bad influence against the measurement result performed by analytical equipment and quality keeping controls at various kinds of production processes are resolved into liquid (deaerated liquid) contacted with the transmission film.
The vacuum deaeration device of the present invention accomplishing the aforesaid object is a vacuum deaeration device in which a transmission film for allowing only gas to pass therethrough and preventing liquid from being transmitted is mounted within a vacuum container. A pressure within the vacuum container is reduced to cause resolved gas to be deaerated from the deaerated liquid through the transmission film. Applied to the transmission film is a product of relatively high volatility in which dispersion liquid composed of a single, not containing both aromatic, and olefin substances is added to a particle plastic substrate to form a paste material that is extruded and baked.
In one preferred embodiment of the present invention, the dispersion liquid is a single solution of linear chain-like paraffin, not containing unsaturated hydrocarbon or having a volatile characteristic and not containing aromatic substances and olefin substances, while the plastic substrate is polytetrafluoroethylene (PTFE).